Table 2.

Mortality Hazard Ratios^a for Measured or Self-Reported Categories of Body Mass Index According to Sex in the Full and Restricted^b Samples From National Health and Nutrition Examination Survey II (1976–1980), III (1988–1994), and Continuous (1999–2010), United States

Sample and BMI Ascertainment Method	BMI Category
	Low (<22.5)		Overweight (25–29.9)		Class I Obesity (30–34.9)		Class II–III Obesity (≥35)
	HR	95% CI	HR	95% CI	HR	95% CI	HR	95% CI
Men
Full sample
Measuredc	1.28	1.13, 1.45	0.94	0.86, 1.02	1.08	0.95, 1.22	1.70	1.42, 2.03
Self-reportedd	1.30	1.16, 1.44	0.97	0.89, 1.05	1.07	0.94, 1.22	1.83	1.52, 2.20
Restricted sample
Measuredc	0.87	0.56, 1.36	0.85	0.62, 1.17	1.13	0.78, 1.64	1.86	1.12, 3.07
Self-reportedd	1.26	0.82, 1.94	1.24	0.90, 1.70	1.26	0.84, 1.90	2.88	1.76, 4.72
Women
Full sample
Measuredc	1.19	1.05, 1.34	1.09	0.97, 1.23	1.30	1.15, 1.48	1.65	1.40, 1.94
Self-reportedd	1.18	1.07, 1.31	1.13	1.02, 1.24	1.37	1.21, 1.54	1.69	1.42, 2.02
Restricted
Measuredc	1.37	1.04, 1.81	1.21	0.96, 1.52	1.59	1.24, 2.03	1.94	1.49, 2.54
Self-reportedd	1.15	0.91, 1.45	1.11	0.88, 1.39	1.48	1.14, 1.91	1.81	1.34, 2.46

Abbreviations: BMI, body mass index; CI, confidence interval; HR, hazard ratio.

^a Hazard ratios from Cox proportional hazards models, with age as the timeline and adjusted for survey, smoking status, racial/ethnic group, and alcohol consumption. The reference category was BMI of 22.5–24.9.

^b The restricted sample was limited to participants who reported never smoking, who reported no history of heart disease or cancer, and who were examined when younger than age 70 years.

^c Measured BMI was calculated from measured height and measured weight as weight (kg)/height (m)².

^d Self-reported BMI was calculated from self-reported weight and self-reported height as weight (kg)/height (m)².